<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>与浏览器拍皮球</title>
		<style type="text/css">
			* {
				margin: 0;
				padding: 0;
			}
			body {
				height: 100vh;
				background-color: #34495e;
				display: flex;
				justify-content: center;
			}
			div {
				width: 50px;
				height: 50px;
				background-color: #3498db;
				border-radius: 50%;
				border: 10px solid white;
				animation: move 1s ease-in-out infinite alternate forwards;
			}
			@keyframes move {
				from {
					transform: translate(0,0vh) scaleY(1.1);
				}
				to {
					transform: translate(0,90vh) scaleX(1.3); 
				}
			}
		</style>
	</head>
	<body>
		<div></div>
	</body>
</html>
